Historically, research supported by this Program Project has contributed significantly to our basic understanding of the neuroendocrinological control of reproduction and growth. Continuing with this objective, the current renewal application contains projects aimed at elucidating the complex mechanisms regulating ovarian follicle growth and differentiation. A multidisciplinary approach will be utilized in which regulation of follicular growth and differentiation will be examined at the molecular, cellular and organismic levels. Specifically, projects are proposed to: (1) isolate and identify all the polypeptide growth factors present in follicular fluid as these factors may have inherent autocrine/paracrine roles in regulating folliculogenesis; (2) explore the regulation and intragonadal action of insulin-like growth factor-binding proteins; (3) ascertain the physiological importance of follistatin in reproduction; and (4) study the regulation of follistatin at the gene level. Experiments proposed in this Program Project will be supported by four Core Units. These Core Units will be established to: (A) maintain and improve the methodology for amino acid analysis and microsequencing to characterize polypeptides, as well as maintain the peptide synthesis facility to provide synthetic peptides for all of the research projects for biological studies and raising of antibodies; (B) maintain the molecular biology facility to perform routine DNA sequencing, oligonucleotide synthesis and preparation of ribo-probes for in situ hybridization studies; (C) provide a central facility for the development and performance of radioimmunoassays and (D) provide a centralized administrative core facility to oversee the daily operation of the Program Project.